flag = "-12;6,-8;10,-6;8,-8;6,-10;8:-9;3,-7;1,-5;7:-6;0,-4;-2,0;2,-2;4:1;1,3;-1,2;0,-2;-4:5;-5,8;-5:2;4,6;4,4;7,6;8,2;8:7;8,10;8,10;6,10;4,7;4,8;6"

d = flag.split(":")

l = []
for i in d:
    t = i.split(",")
    ll = []
    for j in t:
        ll.append(j.replace(";", ","))
    l.append(ll)

print(l)


# OUTPUT:
'''
P:  ['-12,6', '-8,10', '-6,8', '-8,6', '-10,8'],
L:  ['-9,3', '-7,1', '-5,7'],
0:  ['-6,0', '-4,-2', '0,2', '-2,4'],
T:  ['1,1', '3,-1', '2,0', '-2,-4'],
_:  ['5,-5', '8,-5'],
M:  ['2,4', '6,4', '4,7', '6,8', '2,8'],
3:  ['7,8', '10,8', '10,6', '10,4', '7,4', '8,6']]
'''